{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2017:YETFETLEWI45EYFPSYEIVI7QLK","short_pith_number":"pith:YETFETLE","canonical_record":{"source":{"id":"1704.00568","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cs.CE","submitted_at":"2017-04-03T13:19:49Z","cross_cats_sorted":["cs.NA","math.NA"],"title_canon_sha256":"3b97ad5929d3422a491ad213c4f24e90da02b7ad1c98063fbad2cc3f60a48532","abstract_canon_sha256":"3d5bead47838748bc38669ddfebd993960b795bb985cdfa31d12fe323216345c"},"schema_version":"1.0"},"canonical_sha256":"c126524d64b239d260af96088aa3f05aa95658fa31d25a6fb80f2f93b3773417","source":{"kind":"arxiv","id":"1704.00568","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1704.00568","created_at":"2026-06-04T18:10:42Z"},{"alias_kind":"arxiv_version","alias_value":"1704.00568v1","created_at":"2026-06-04T18:10:42Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1704.00568","created_at":"2026-06-04T18:10:42Z"},{"alias_kind":"pith_short_12","alias_value":"YETFETLEWI45","created_at":"2026-06-04T18:10:42Z"},{"alias_kind":"pith_short_16","alias_value":"YETFETLEWI45EYFP","created_at":"2026-06-04T18:10:42Z"},{"alias_kind":"pith_short_8","alias_value":"YETFETLE","created_at":"2026-06-04T18:10:42Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2017:YETFETLEWI45EYFPSYEIVI7QLK","target":"record","payload":{"canonical_record":{"source":{"id":"1704.00568","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cs.CE","submitted_at":"2017-04-03T13:19:49Z","cross_cats_sorted":["cs.NA","math.NA"],"title_canon_sha256":"3b97ad5929d3422a491ad213c4f24e90da02b7ad1c98063fbad2cc3f60a48532","abstract_canon_sha256":"3d5bead47838748bc38669ddfebd993960b795bb985cdfa31d12fe323216345c"},"schema_version":"1.0"},"canonical_sha256":"c126524d64b239d260af96088aa3f05aa95658fa31d25a6fb80f2f93b3773417","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-06-04T18:10:42.641411Z","signature_b64":"ljnxFKARCQMltkbeItAVqkheLn05lOMyEVAXmj4t2Lfpk3gdriXmjLV8G10KfIfUwa9CUlf/AM6hatJKPrcuCA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"c126524d64b239d260af96088aa3f05aa95658fa31d25a6fb80f2f93b3773417","last_reissued_at":"2026-06-04T18:10:42.640952Z","signature_status":"signed_v1","first_computed_at":"2026-06-04T18:10:42.640952Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1704.00568","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-06-04T18:10:42Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"lVE6ruurEAjIqfX3g0EuuB6cVGR1vzWvlgd8T8hUhDc1z1Y1WRI6sxgBHd9zkRxu+YymWlCXCf4XMD0UlIvBCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-10T21:07:51.551138Z"},"content_sha256":"122e6608f5da5fd34eaaac95a3d0c7d3b8df5e7f14f7b590e79188d441aa85a3","schema_version":"1.0","event_id":"sha256:122e6608f5da5fd34eaaac95a3d0c7d3b8df5e7f14f7b590e79188d441aa85a3"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2017:YETFETLEWI45EYFPSYEIVI7QLK","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"A parametric level-set method for partially discrete tomography","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["cs.NA","math.NA"],"primary_cat":"cs.CE","authors_text":"Ajinkya Kadu, K. Joost Batenburg, Tristan van Leeuwen","submitted_at":"2017-04-03T13:19:49Z","abstract_excerpt":"This paper introduces a parametric level-set method for tomographic reconstruction of partially discrete images. Such images consist of a continuously varying background and an anomaly with a constant (known) grey-value. We represent the geometry of the anomaly using a level-set function, which we represent using radial basis functions. We pose the reconstruction problem as a bi-level optimization problem in terms of the background and coefficients for the level-set function. To constrain the background reconstruction we impose smoothness through Tikhonov regularization. The bi-level optimizat"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1704.00568","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/1704.00568/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-06-04T18:10:42Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"wjp8v1XC/Xxf4NLpz6izmG1hjNgQCBMUmGh8iysVZ7IYIKmibhRDk6INyHV/QXzbWRPOBA7VC4777iI08bKkDQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-10T21:07:51.551556Z"},"content_sha256":"9b32ed248c4108a1aa459a87f61db40b335de2a7e0a6a2c63f0f8fcfe4f647ed","schema_version":"1.0","event_id":"sha256:9b32ed248c4108a1aa459a87f61db40b335de2a7e0a6a2c63f0f8fcfe4f647ed"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/YETFETLEWI45EYFPSYEIVI7QLK/bundle.json","state_url":"https://pith.science/pith/YETFETLEWI45EYFPSYEIVI7QLK/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/YETFETLEWI45EYFPSYEIVI7QLK/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-07-10T21:07:51Z","links":{"resolver":"https://pith.science/pith/YETFETLEWI45EYFPSYEIVI7QLK","bundle":"https://pith.science/pith/YETFETLEWI45EYFPSYEIVI7QLK/bundle.json","state":"https://pith.science/pith/YETFETLEWI45EYFPSYEIVI7QLK/state.json","well_known_bundle":"https://pith.science/.well-known/pith/YETFETLEWI45EYFPSYEIVI7QLK/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2017:YETFETLEWI45EYFPSYEIVI7QLK","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"3d5bead47838748bc38669ddfebd993960b795bb985cdfa31d12fe323216345c","cross_cats_sorted":["cs.NA","math.NA"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cs.CE","submitted_at":"2017-04-03T13:19:49Z","title_canon_sha256":"3b97ad5929d3422a491ad213c4f24e90da02b7ad1c98063fbad2cc3f60a48532"},"schema_version":"1.0","source":{"id":"1704.00568","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1704.00568","created_at":"2026-06-04T18:10:42Z"},{"alias_kind":"arxiv_version","alias_value":"1704.00568v1","created_at":"2026-06-04T18:10:42Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1704.00568","created_at":"2026-06-04T18:10:42Z"},{"alias_kind":"pith_short_12","alias_value":"YETFETLEWI45","created_at":"2026-06-04T18:10:42Z"},{"alias_kind":"pith_short_16","alias_value":"YETFETLEWI45EYFP","created_at":"2026-06-04T18:10:42Z"},{"alias_kind":"pith_short_8","alias_value":"YETFETLE","created_at":"2026-06-04T18:10:42Z"}],"graph_snapshots":[{"event_id":"sha256:9b32ed248c4108a1aa459a87f61db40b335de2a7e0a6a2c63f0f8fcfe4f647ed","target":"graph","created_at":"2026-06-04T18:10:42Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/1704.00568/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"This paper introduces a parametric level-set method for tomographic reconstruction of partially discrete images. Such images consist of a continuously varying background and an anomaly with a constant (known) grey-value. We represent the geometry of the anomaly using a level-set function, which we represent using radial basis functions. We pose the reconstruction problem as a bi-level optimization problem in terms of the background and coefficients for the level-set function. To constrain the background reconstruction we impose smoothness through Tikhonov regularization. The bi-level optimizat","authors_text":"Ajinkya Kadu, K. Joost Batenburg, Tristan van Leeuwen","cross_cats":["cs.NA","math.NA"],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cs.CE","submitted_at":"2017-04-03T13:19:49Z","title":"A parametric level-set method for partially discrete tomography"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1704.00568","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:122e6608f5da5fd34eaaac95a3d0c7d3b8df5e7f14f7b590e79188d441aa85a3","target":"record","created_at":"2026-06-04T18:10:42Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"3d5bead47838748bc38669ddfebd993960b795bb985cdfa31d12fe323216345c","cross_cats_sorted":["cs.NA","math.NA"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cs.CE","submitted_at":"2017-04-03T13:19:49Z","title_canon_sha256":"3b97ad5929d3422a491ad213c4f24e90da02b7ad1c98063fbad2cc3f60a48532"},"schema_version":"1.0","source":{"id":"1704.00568","kind":"arxiv","version":1}},"canonical_sha256":"c126524d64b239d260af96088aa3f05aa95658fa31d25a6fb80f2f93b3773417","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"c126524d64b239d260af96088aa3f05aa95658fa31d25a6fb80f2f93b3773417","first_computed_at":"2026-06-04T18:10:42.640952Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-06-04T18:10:42.640952Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"ljnxFKARCQMltkbeItAVqkheLn05lOMyEVAXmj4t2Lfpk3gdriXmjLV8G10KfIfUwa9CUlf/AM6hatJKPrcuCA==","signature_status":"signed_v1","signed_at":"2026-06-04T18:10:42.641411Z","signed_message":"canonical_sha256_bytes"},"source_id":"1704.00568","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:122e6608f5da5fd34eaaac95a3d0c7d3b8df5e7f14f7b590e79188d441aa85a3","sha256:9b32ed248c4108a1aa459a87f61db40b335de2a7e0a6a2c63f0f8fcfe4f647ed"],"state_sha256":"a32643d6e80e0adf362e6eb700a466594b6d82df9879c3a94637b211bb3d7b0a"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ujO+1lPwZtFJrwyIMy8TRr76HWooW7N6m7DacQEFaTriYEkaGgf3oUwi3dm0YqR+gXpolZ9XBV3lX4E40D5HAw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-10T21:07:51.554025Z","bundle_sha256":"365bae3ffa8ab988bd16d473c6719323ba68f14a07f77991a799d797a5751bf3"}}